Vodacom contract *****

I was a loyal Vodacom customer for over 20 years. I went into a store on 30/03/2026 to cancel my contract and paid the early cancellation fees. Then months later, they start deducting money from my account which I did not authorise. I reached out to them but got no response, so I assumed a *****ulent transaction and reversed it at the bank. This morning I received a collection notice/threat for a contract I cancelled. This is not acceptable! I cancelled my contract months ago.